Production and secretion of intrinsic factor by isolated rabbit gastric mucosa

1986 ◽  
Vol 251 (3) ◽  
pp. G287-G292
Author(s):  
D. Serfilippi ◽  
R. M. Donaldson

During 24 h of organ culture, rabbit gastric fundic mucosal explants maintain constant tissue levels of intrinsic factor (IF) while steadily secreting this glycoprotein into culture medium. Mucosal explants thus generate in one day an average of 1.8 pmol of new IF per milligram mucosal protein, an amount corresponding to 70% of IF present in explant tissue. Cultured explants also incorporate [35S]methionine into tissue IF and secreted IF at a constant rate. Histamine combined with isobutylmethylxanthine stimulates explants to release IF into the culture medium, but tissue levels of IF are diminished and specific activities of tissue and secreted IF remain the same. Fluorograms of 35S-labeled proteins generated by cultured explants fail to show cobalamin-binding precursors or breakdown products of IF. These findings complement previous morphological documentation of IF synthesis by gastric mucosa. Histamine appears to stimulate IF secretion without altering IF synthesis.

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 465-470
Author(s):  
Charles L. Foote ◽  
Florence M. Foote

Earlier reports (Foote & Foote, 1958a, b, 1959) describe growth and maintenance in vitro of larval organs, particularly gonads, of Rana catesbeiana and Xenopus laevis. Immature germ cells of both testes and ovaries are well maintained in vitro, especially if the culture medium is supplemented with watersoluble sex-hormonal substances, although germ cells in process of maturation become necrotic. Recently some urogenital organs from the salamander, Pleurodeles waltlii, have been grown in vitro. Tissues and organs from this amphibian might prove to be more suitable for tissue and organ culture investigations than those of Anurans. Animals at three different ages were used in this study: recently hatched larvae, metamorphosing animals, and adults. To determine whether sex differentiation would occur in vitro, trunk portions of young larvae of Pleurodeles waltlii of developmental stages 37–38 (Gallien & Durocher, 1957) were placed in organ cultures.


Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 407-414
Author(s):  
R. Christy Armstrong ◽  
Joel J. Elias

Abnormalities of the ocular system which appear in organ culture in Waymouth's medium with freshly added glutamine (Armstrong & Elias, 1968) resemble those caused by transitory pteryolglutamic acid (PGA or folic acid) deficiency in vivo (Armstrong & Monie, 1966). The configurations of such malformations as lens herniations, retinal diverticula, and rosette-like formations of the retina are remarkably similar in both cases. The experiments reported in this paper were undertaken in an effort to understand the mechanisms involved in the production of similar abnormalities by two very different experimental conditions: the addition of glutamine in vitro and the transitory deficiency of PGA in vivo. One series of experiments involved the effects of manipulation of the PGA and glutamine content of the culture medium on eye development in vitro. Parallel studies on PGA-deficiency in vivo were undertaken in conjunction with organ-culture experiments in order to compare the effects on abnormal eye morphogenesis.


1965 ◽  
Vol 208 (3) ◽  
pp. 528-530 ◽  
Author(s):  
Horace W. Davenport ◽  
Peter H. Abbrecht

Frog gastric mucosa was formed into a sac, filled with 1 ml salt solution and incubated in a large volume of identical salt solution containing 3 mm potassium and K42. Total potassium and specific activities of tissue and fluid were measured at 5, 10, 20, 40, 80, and 160 min after start of incubation. The measurements were repeated on mucosas formed into sacs with the mucosal side out. Both types of sacs were also incubated in solutions containing 0.1 mm histamine. Results confirm observations of others that there is net movement of potassium from fluid bathing the serosal surface into the tissue and mucosal fluid and that histamine stimulates potassium movement from tissue into mucosal fluid. The data were used to calculate the ratio of the rate of movement of potassium across the serosal and mucosal surfaces, Rs/Rm. The numerical value of 4.72 was obtained without histamine and 7.16 with histamine.


Gut ◽  
2019 ◽  
Vol 69 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
Kevin A Bockerstett ◽  
Scott A Lewis ◽  
Kyle J Wolf ◽  
Christine N Noto ◽  
Nicholas M Jackson ◽  
...  

ObjectiveSpasmolytic polypeptide-expressing metaplasia (SPEM) is a regenerative lesion in the gastric mucosa and is a potential precursor to intestinal metaplasia/gastric adenocarcinoma in a chronic inflammatory setting. The goal of these studies was to define the transcriptional changes associated with SPEM at the individual cell level in response to acute drug injury and chronic inflammatory damage in the gastric mucosa.DesignEpithelial cells were isolated from the gastric corpus of healthy stomachs and stomachs with drug-induced and inflammation-induced SPEM lesions. Single cell RNA sequencing (scRNA-seq) was performed on tissue samples from each of these settings. The transcriptomes of individual epithelial cells from healthy, acutely damaged and chronically inflamed stomachs were analysed and compared.ResultsscRNA-seq revealed a population Mucin 6 (Muc6)+gastric intrinsic factor (Gif)+ cells in healthy tissue, but these cells did not express transcripts associated with SPEM. Furthermore, analyses of SPEM cells from drug injured and chronically inflamed corpus yielded two major findings: (1) SPEM and neck cell hyperplasia/hypertrophy are nearly identical in the expression of SPEM-associated transcripts and (2) SPEM programmes induced by drug-mediated parietal cell ablation and chronic inflammation are nearly identical, although the induction of transcripts involved in immunomodulation was unique to SPEM cells in the chronic inflammatory setting.ConclusionsThese data necessitate an expansion of the definition of SPEM to include Tff2+Muc6+ cells that do not express mature chief cell transcripts such as Gif. Our data demonstrate that SPEM arises by a highly conserved cellular programme independent of aetiology and develops immunoregulatory capabilities in a setting of chronic inflammation.


1988 ◽  
Vol 66 (7) ◽  
pp. 901-906 ◽  
Author(s):  
Hikaru Tanaka ◽  
Yutaka Kasuya ◽  
Hiroshi Saito ◽  
Koki Shigenobu

Changes in sensitivity to norepinephrine (NE) of fetal and neonatal rat right atria placed in organ culture were examined. The high sensitivity to NE of the 17-day fetal atria was maintained during organ culture for 5 days. The pD2 value for NE at the 17th day of gestation was 8.66 ± 0.09, and that after organ culture for 5 days was 8.62 ± 0.09. The sensitivity of 1-day-old neonatal artia was significantly lower than that of fetal atria; but when they were cultured for 24 h, there was a 10-fold increase in sensitivity. The pD2 value before culture was 7.59 ± 0.05, and that after culture was 8.54 ± 0.04. NE added to the culture medium prevented this increase in sensitivity. Similar changes were observed in the sensitivity to isoproterenol, but not in the sensitivity to forskolin, indicating that these sensitivity changes were of a postjunctional nature and most likely due to some changes in the β-receptor and (or) its coupling to adenylate cyclase. Therefore, the decrease in myocardial sensitivity to NE observed during the late fetal period is most likely to be caused by factor(s) related to sympathetic innervation.


1975 ◽  
Vol 148 (2) ◽  
pp. 309-320 ◽  
Author(s):  
B K Speake ◽  
R Dils ◽  
R J Mayer

1. Explants of mammary gland from mid-pregnant rabbits were cultured with insulin, prolactin and cortisol. 2. Antibodies raised to fatty acid synthetase were used to measure the amount as well as the rate of synthesis and the rate of degradation of the enzyme in the explants over defined periods in organ culture. These measurements were also made after the hormones had been removed from the culture medium. The changes which occur in the activity of fatty acid synthetase are due to changes in the amount of the enzyme present. They are not due to activation or inactivation of the enzyme. 3. The rate of lipogenesis (measured from [1-14C]acetate) in the explants during culture varies independently of the amount of fatty acid synthetase both in the presence and after removal of the hormones. Hence the amount of fatty acid synthetase does not limit lipogenesis. The proportion of medium-chain fatty acids C8:0 and C10:0 (which are characteristic of rabbit milk) synthesized by the explants in the presence of hormones increases at about the same rate as the amount of fatty acid synthetase present. However, when hormones are removed from the medium the proportion of these acids synthesized declines as rapidly as the rate of lipogenesis and not as the amount of fatty acid synthetase presen. 4. The rates of synthesis of fatty acid synthetase and of the total particulate-free supernatant protein in the explants were compared by measuring the incorporation of L-[U-14C]leucine into the protein of the explants. These rates increase by 5-fold and 3.6-fold respectively when explants are cultured with hormones, and they then reach approximately constant rates. When the hormones are removed there is a rapid fall in the rate of synthesis of fatty acid synthetase and of the total particulate-free supernatant protein to values which are similar to those obtained with freshly prepared explanted tissue. 5. In unstimulated explants fatty acid synthetase appears to be degraded with a half-life of 15-21h. During the hormonally stimulated differentiation of the tissue the rate of degradation of the enzyme is considerably decreased or is switched off completely. After the amount of fatty acid synthetase has increased to a maximum the enzyme complex is again degraded with a half-life of 23-29h. The removal of hormones after the explants have been hormonally stimulated for different times results in an increase in the rate of degradation of fatty acid synthetase. However, this increase only occurs if degradation was previously proceeding at a considerably decreased rate. The degradation of the total particulate-free supernatant protein continues throughout the period of differentiation of the explant tissue in culture. It appears to be somewhat decreased during the period of rapid maturation of the tissue during culture.


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